20200803--iOS之Calendar结构体，表示日历
Structure
Calendar
A definition of the relationships between calendar units (such as eras, years, and weekdays) and absolute points in time, providing features for calculation and comparison of dates.
--日历单位（如纪元、年和工作日）与绝对时间点之间关系的定义，提供日期的计算和比较功能。
Declaration
struct CalendarOverview --概览
Calendar encapsulates information about systems of reckoning time in which the beginning, length, and divisions of a year are defined. It provides information about the calendar and support for calendrical computations such as determining the range of a given calendrical unit and adding units to a given absolute time.
--日历封装了有关计算时间系统的信息，其中定义了一年的开始、长度和分区。它提供有关日历的信息，并支持日历计算，如确定给定日历单位的范围，以及向给定的绝对时间添加单位。
Topics --专题
Creating a Calendar --创建日历
enum Calendar.Identifier
An enumeration for the available calendars.
Getting the User's Calendar --获取用户的日历
static var autoupdatingCurrent: Calendar
A calendar that tracks changes to user’s preferred calendar.
static var current: Calendar
The user’s current calendar.
Extracting Components --抽取日历组件
func date(Date, matchesComponents: DateComponents) -> Bool
Determines if the date has all of the specified date components. --判断日期是否包含参数中所有的日期组件。
func component(Calendar.Component, from: Date) -> Int
Returns the value for one component of a date. --返回参数中日期的一个组件的值。
func dateComponents(Set
Returns all the date components of a date, using the calendar time zone. --使用日历时区返回日期的所有日期组件。
func dateComponents(Set
Returns the difference between two dates.
func dateComponents(Set
Returns the difference between two dates specified as DateComponents.
func dateComponents(in: TimeZone, from: Date) -> DateComponents
Returns all the date components of a date, as if in a given time zone (instead of the Calendar time zone).
enum Calendar.Component
An enumeration for the various components of a calendar date.
Getting Calendar Information --获取日历信息
var identifier: Calendar.Identifier
The identifier of the calendar.
var locale: Locale?
The locale of the calendar.
var firstWeekday: Int
The first weekday of the calendar.
var minimumDaysInFirstWeek: Int
The number of minimum days in the first week.
var timeZone: TimeZone
The time zone of the calendar.
func maximumRange(of: Calendar.Component) -> Range
The maximum range limits of the values that a given component can take on.
func minimumRange(of: Calendar.Component) -> Range
Returns the minimum range limits of the values that a given component can take on.
func ordinality(of: Calendar.Component, in: Calendar.Component, for: Date) -> Int?
Returns, for a given absolute time, the ordinal number of a smaller calendar component (such as a day) within a specified larger calendar component (such as a week).
func range(of: Calendar.Component, in: Calendar.Component, for: Date) -> Range
Returns the range of absolute time values that a smaller calendar component (such as a day) can take on in a larger calendar component (such as a month) that includes a specified absolute time.
Scanning Dates --遍历日期
func startOfDay(for: Date) -> Date
Returns the first moment of a given Date, as a Date.
func enumerateDates(startingAfter: Date, matching: DateComponents, matchingPolicy: Calendar.MatchingPolicy, repeatedTimePolicy: Calendar.RepeatedTimePolicy, direction: Calendar.SearchDirection, using: (Date?, Bool, inout Bool) -> Void)
Computes the dates which match (or most closely match) a given set of components, and calls the closure once for each of them, until the enumeration is stopped.
func nextDate(after: Date, matching: DateComponents, matchingPolicy: Calendar.MatchingPolicy, repeatedTimePolicy: Calendar.RepeatedTimePolicy, direction: Calendar.SearchDirection) -> Date?
Computes the next date which matches (or most closely matches) a given set of components.
enum Calendar.MatchingPolicy
A hint to the search algorithm to control the method used for searching for dates.
enum Calendar.RepeatedTimePolicy
Determines which result to use when a time is repeated on a day in a calendar (for example, during a daylight saving transition when the times between 2:00am and 3:00am may happen twice).
Calculating Dates from Components --从组件中计算日期
func date(from: DateComponents) -> Date?
Returns a date created from the specified components.
func date(byAdding: DateComponents, to: Date, wrappingComponents: Bool) -> Date?
Returns a new Date representing the date calculated by adding components to a given date.
func date(byAdding: Calendar.Component, value: Int, to: Date, wrappingComponents: Bool) -> Date?
Returns a new Date representing the date calculated by adding an amount of a specific component to a given date.
func date(bySetting: Calendar.Component, value: Int, of: Date) -> Date?
Returns a new Date representing the date calculated by setting a specific component to a given time, and trying to keep lower components the same. If the component already has that value, this may result in a date which is the same as the given date.
func date(bySettingHour: Int, minute: Int, second: Int, of: Date, matchingPolicy: Calendar.MatchingPolicy, repeatedTimePolicy: Calendar.RepeatedTimePolicy, direction: Calendar.SearchDirection) -> Date?
Returns a new Date representing the date calculated by setting hour, minute, and second to a given time on a specified Date.
Calculating Intervals --计算时间间隔
func dateInterval(of: Calendar.Component, for: Date) -> DateInterval?
Returns the starting time and duration of a given calendar component that contains a given date.
func dateInterval(of: Calendar.Component, start: inout Date, interval: inout TimeInterval, for: Date) -> Bool
Returns, via two inout parameters, the starting time and duration of a given calendar component that contains a given date.
func dateIntervalOfWeekend(containing: Date) -> DateInterval?
Returns a DateInterval of the weekend contained by the given date, or nil if the date is not in a weekend.
func dateIntervalOfWeekend(containing: Date, start: inout Date, interval: inout TimeInterval) -> Bool
Find the range of the weekend around the given date, returned via two by-reference parameters.
func nextWeekend(startingAfter: Date, direction: Calendar.SearchDirection) -> DateInterval?
Returns a DateInterval of the next weekend, which starts strictly after the given date.
func nextWeekend(startingAfter: Date, start: inout Date, interval: inout TimeInterval, direction: Calendar.SearchDirection) -> Bool
Returns the range of the next weekend via two inout parameters. The weekend starts strictly after the given date.
enum Calendar.SearchDirection
The direction in time to search.
Comparing Dates --比较日期
func compare(Date, to: Date, toGranularity: Calendar.Component) -> ComparisonResult
Compares two dates down to the specified component.
func isDate(Date, equalTo: Date, toGranularity: Calendar.Component) -> Bool
Returns a Boolean value indicating whether two dates are equal down to the specified component.
func isDate(Date, inSameDayAs: Date) -> Bool
Returns a Boolean value indicating whether a date is within the same day as another date.
func isDateInToday(Date) -> Bool
Returns a Boolean value indicating whether the given date is within today.
func isDateInTomorrow(Date) -> Bool
Returns a Boolean value indicating whether the given date is within tomorrow.
func isDateInYesterday(Date) -> Bool
Returns a Boolean value indicating whether the given date is within yesterday.
func isDateInWeekend(Date) -> Bool
Returns a Boolean value indicating whether the given date is within a weekend period.
Comparing Calendars --比较日历
static func == (Calendar, Calendar) -> Bool
Returns a Boolean indicating whether two calendars are the same.
static func != (Calendar, Calendar) -> Bool
Returns a Boolean value indicating whether two values are not equal.
Getting AM and PM symbols --获取上下午符号
var amSymbol: String
The symbol used to represent “AM”, localized to the Calendar’s locale.
var pmSymbol: String
The symbol used to represent “PM”, localized to the Calendar’s locale.
Getting Weekday Symbols --获取星期几的符号
var weekdaySymbols: [String]
A list of weekdays in this calendar, localized to the Calendar’s locale.
var shortWeekdaySymbols: [String]
A list of shorter-named weekdays in this calendar, localized to the Calendar’s locale.
var veryShortWeekdaySymbols: [String]
A list of very-shortly-named weekdays in this calendar, localized to the Calendar’s locale.
var standaloneWeekdaySymbols: [String]
A list of standalone weekday names in this calendar, localized to the Calendar’s locale.
var shortStandaloneWeekdaySymbols: [String]
A list of shorter-named standalone weekdays in this calendar, localized to the Calendar’s locale.
var veryShortStandaloneWeekdaySymbols: [String]
A list of very-shortly-named weekdays in this calendar, localized to the Calendar’s locale.
Getting Month Symbols --获取某月几号的字符串
var monthSymbols: [String]
A list of months in this calendar, localized to the Calendar’s locale.
var shortMonthSymbols: [String]
A list of shorter-named months in this calendar, localized to the Calendar’s locale.
var veryShortMonthSymbols: [String]
A list of very-shortly-named months in this calendar, localized to the Calendar’s locale.
var standaloneMonthSymbols: [String]
A list of standalone months in this calendar, localized to the Calendar’s locale.
var shortStandaloneMonthSymbols: [String]
A list of shorter-named standalone months in this calendar, localized to the Calendar’s locale.
var veryShortStandaloneMonthSymbols: [String]
A list of very-shortly-named standalone months in this calendar, localized to the Calendar’s locale.
Getting Quarter Symbols --获取季节的符号
var quarterSymbols: [String]
A list of quarter names in this calendar, localized to the Calendar’s locale.
var shortQuarterSymbols: [String]
A list of shorter-named quarters in this calendar, localized to the Calendar’s locale.
var standaloneQuarterSymbols: [String]
A list of standalone quarter names in this calendar, localized to the Calendar’s locale.
var shortStandaloneQuarterSymbols: [String]
A list of shorter-named standalone quarters in this calendar, localized to the Calendar’s locale.
Getting Era Symbols --获取纪元的符号
var eraSymbols: [String]
A list of eras in this calendar, localized to the Calendar’s locale.
var longEraSymbols: [String]
A list of longer-named eras in this calendar, localized to the Calendar’s locale.
Describing a Calendar --描述一个日历
var description: String
A textual description of the calendar.
var debugDescription: String
A textual description of the locale suitable for debugging.
var customMirror: Mirror
A mirror that reflects the calendar.
var hashValue: Int
The computed hash value for the calendar.
Encoding and Decoding --编码和解码
func encode(to: Encoder)
Encodes this calendar into the given encoder.
init(from: Decoder)
Creates a new calendar instance by decoding from the given decoder.
Using Reference Types --使用引用类型
class NSCalendar
An encapsulation of calendar information and calculations that bridges to Calendar; use NSCalendar when you need reference semantics or other Foundation-specific behavior.4
typealias Calendar.ReferenceType
An alias for this value type's equivalent reference type.
Initializers --构造器
init(identifier: Calendar.Identifier)
Instance Methods --实例方法
func hash(into: inout Hasher)
Relationships
Conforms To
CustomDebugStringConvertibleCustomReflectableCustomStringConvertibleDecodableEncodableEquatableHashableReferenceConvertible
See Also
Calendrical Calculations
struct DateComponents
A date or time specified in terms of units (such as year, month, day, hour, and minute) to be evaluated in a calendar system and time zone.
struct TimeZone
Information about standard time conventions associated with a specific geopolitical region.